Hand held non-contact voltage tester

Abstract

A non-contact voltage tester has a self-test feature so that when a switch clip of the tester is actuated, light and sound indicator devices are energized to give a single blink and beep, respectively, following which the tester is ready for probing for a voltage. The light and sound indicator devices also indicate the presence of a voltage when the switch is actuated and a voltage is detected at the probe tip of the tester.

We claim: 
     
       1. In a non-contact voltage tester of the type having a single probe tip for sensing the presence of a voltage, an indicating lamp for signalling a user of the tester when said voltage is present, circuitry for detecting a voltage at said probe tip and operating said indicating lamp in response to said detected voltage, a battery power supply for energizing said circuitry and a switch actuated by the user of said tester for operatively connecting said power supply with said circuitry, the improvement wherein said indicating lamp emits a signal of limited duration to the operator when said switch is first actuated by the user in the absence of a voltage detected by said circuitry at said probe tip and said lamp is positioned inside a translucent section of a housing of said tester, said lamp and translucent section being positioned between said switch and said probe tip. 
     
     
       2. The improvement as defined in claim 1, wherein said tester includes a sound source which is activated when said lamp is activated. 
     
     
       3. The improvement as defined in claim 1, wherein light emitted by said lamp and transmitted by said translucent section is visible for 360° around a longitudinal axis of said tester.